linux/fs/ocfs2/stack_o2cb.c
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   1/* -*- mode: c; c-basic-offset: 8; -*-
   2 * vim: noexpandtab sw=8 ts=8 sts=0:
   3 *
   4 * stack_o2cb.c
   5 *
   6 * Code which interfaces ocfs2 with the o2cb stack.
   7 *
   8 * Copyright (C) 2007 Oracle.  All rights reserved.
   9 *
  10 * This program is free software; you can redistribute it and/or
  11 * modify it under the terms of the GNU General Public
  12 * License as published by the Free Software Foundation, version 2.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17 * General Public License for more details.
  18 */
  19
  20#include <linux/kernel.h>
  21#include <linux/crc32.h>
  22#include <linux/slab.h>
  23#include <linux/module.h>
  24
  25/* Needed for AOP_TRUNCATED_PAGE in mlog_errno() */
  26#include <linux/fs.h>
  27
  28#include "cluster/masklog.h"
  29#include "cluster/nodemanager.h"
  30#include "cluster/heartbeat.h"
  31#include "cluster/tcp.h"
  32
  33#include "stackglue.h"
  34
  35struct o2dlm_private {
  36        struct dlm_eviction_cb op_eviction_cb;
  37};
  38
  39static struct ocfs2_stack_plugin o2cb_stack;
  40
  41/* These should be identical */
  42#if (DLM_LOCK_IV != LKM_IVMODE)
  43# error Lock modes do not match
  44#endif
  45#if (DLM_LOCK_NL != LKM_NLMODE)
  46# error Lock modes do not match
  47#endif
  48#if (DLM_LOCK_CR != LKM_CRMODE)
  49# error Lock modes do not match
  50#endif
  51#if (DLM_LOCK_CW != LKM_CWMODE)
  52# error Lock modes do not match
  53#endif
  54#if (DLM_LOCK_PR != LKM_PRMODE)
  55# error Lock modes do not match
  56#endif
  57#if (DLM_LOCK_PW != LKM_PWMODE)
  58# error Lock modes do not match
  59#endif
  60#if (DLM_LOCK_EX != LKM_EXMODE)
  61# error Lock modes do not match
  62#endif
  63static inline int mode_to_o2dlm(int mode)
  64{
  65        BUG_ON(mode > LKM_MAXMODE);
  66
  67        return mode;
  68}
  69
  70#define map_flag(_generic, _o2dlm)              \
  71        if (flags & (_generic)) {               \
  72                flags &= ~(_generic);           \
  73                o2dlm_flags |= (_o2dlm);        \
  74        }
  75static int flags_to_o2dlm(u32 flags)
  76{
  77        int o2dlm_flags = 0;
  78
  79        map_flag(DLM_LKF_NOQUEUE, LKM_NOQUEUE);
  80        map_flag(DLM_LKF_CANCEL, LKM_CANCEL);
  81        map_flag(DLM_LKF_CONVERT, LKM_CONVERT);
  82        map_flag(DLM_LKF_VALBLK, LKM_VALBLK);
  83        map_flag(DLM_LKF_IVVALBLK, LKM_INVVALBLK);
  84        map_flag(DLM_LKF_ORPHAN, LKM_ORPHAN);
  85        map_flag(DLM_LKF_FORCEUNLOCK, LKM_FORCE);
  86        map_flag(DLM_LKF_TIMEOUT, LKM_TIMEOUT);
  87        map_flag(DLM_LKF_LOCAL, LKM_LOCAL);
  88
  89        /* map_flag() should have cleared every flag passed in */
  90        BUG_ON(flags != 0);
  91
  92        return o2dlm_flags;
  93}
  94#undef map_flag
  95
  96/*
  97 * Map an o2dlm status to standard errno values.
  98 *
  99 * o2dlm only uses a handful of these, and returns even fewer to the
 100 * caller. Still, we try to assign sane values to each error.
 101 *
 102 * The following value pairs have special meanings to dlmglue, thus
 103 * the right hand side needs to stay unique - never duplicate the
 104 * mapping elsewhere in the table!
 105 *
 106 * DLM_NORMAL:          0
 107 * DLM_NOTQUEUED:       -EAGAIN
 108 * DLM_CANCELGRANT:     -EBUSY
 109 * DLM_CANCEL:          -DLM_ECANCEL
 110 */
 111/* Keep in sync with dlmapi.h */
 112static int status_map[] = {
 113        [DLM_NORMAL]                    = 0,            /* Success */
 114        [DLM_GRANTED]                   = -EINVAL,
 115        [DLM_DENIED]                    = -EACCES,
 116        [DLM_DENIED_NOLOCKS]            = -EACCES,
 117        [DLM_WORKING]                   = -EACCES,
 118        [DLM_BLOCKED]                   = -EINVAL,
 119        [DLM_BLOCKED_ORPHAN]            = -EINVAL,
 120        [DLM_DENIED_GRACE_PERIOD]       = -EACCES,
 121        [DLM_SYSERR]                    = -ENOMEM,      /* It is what it is */
 122        [DLM_NOSUPPORT]                 = -EPROTO,
 123        [DLM_CANCELGRANT]               = -EBUSY,       /* Cancel after grant */
 124        [DLM_IVLOCKID]                  = -EINVAL,
 125        [DLM_SYNC]                      = -EINVAL,
 126        [DLM_BADTYPE]                   = -EINVAL,
 127        [DLM_BADRESOURCE]               = -EINVAL,
 128        [DLM_MAXHANDLES]                = -ENOMEM,
 129        [DLM_NOCLINFO]                  = -EINVAL,
 130        [DLM_NOLOCKMGR]                 = -EINVAL,
 131        [DLM_NOPURGED]                  = -EINVAL,
 132        [DLM_BADARGS]                   = -EINVAL,
 133        [DLM_VOID]                      = -EINVAL,
 134        [DLM_NOTQUEUED]                 = -EAGAIN,      /* Trylock failed */
 135        [DLM_IVBUFLEN]                  = -EINVAL,
 136        [DLM_CVTUNGRANT]                = -EPERM,
 137        [DLM_BADPARAM]                  = -EINVAL,
 138        [DLM_VALNOTVALID]               = -EINVAL,
 139        [DLM_REJECTED]                  = -EPERM,
 140        [DLM_ABORT]                     = -EINVAL,
 141        [DLM_CANCEL]                    = -DLM_ECANCEL, /* Successful cancel */
 142        [DLM_IVRESHANDLE]               = -EINVAL,
 143        [DLM_DEADLOCK]                  = -EDEADLK,
 144        [DLM_DENIED_NOASTS]             = -EINVAL,
 145        [DLM_FORWARD]                   = -EINVAL,
 146        [DLM_TIMEOUT]                   = -ETIMEDOUT,
 147        [DLM_IVGROUPID]                 = -EINVAL,
 148        [DLM_VERS_CONFLICT]             = -EOPNOTSUPP,
 149        [DLM_BAD_DEVICE_PATH]           = -ENOENT,
 150        [DLM_NO_DEVICE_PERMISSION]      = -EPERM,
 151        [DLM_NO_CONTROL_DEVICE]         = -ENOENT,
 152        [DLM_RECOVERING]                = -ENOTCONN,
 153        [DLM_MIGRATING]                 = -ERESTART,
 154        [DLM_MAXSTATS]                  = -EINVAL,
 155};
 156
 157static int dlm_status_to_errno(enum dlm_status status)
 158{
 159        BUG_ON(status < 0 || status >= ARRAY_SIZE(status_map));
 160
 161        return status_map[status];
 162}
 163
 164static void o2dlm_lock_ast_wrapper(void *astarg)
 165{
 166        struct ocfs2_dlm_lksb *lksb = astarg;
 167
 168        lksb->lksb_conn->cc_proto->lp_lock_ast(lksb);
 169}
 170
 171static void o2dlm_blocking_ast_wrapper(void *astarg, int level)
 172{
 173        struct ocfs2_dlm_lksb *lksb = astarg;
 174
 175        lksb->lksb_conn->cc_proto->lp_blocking_ast(lksb, level);
 176}
 177
 178static void o2dlm_unlock_ast_wrapper(void *astarg, enum dlm_status status)
 179{
 180        struct ocfs2_dlm_lksb *lksb = astarg;
 181        int error = dlm_status_to_errno(status);
 182
 183        /*
 184         * In o2dlm, you can get both the lock_ast() for the lock being
 185         * granted and the unlock_ast() for the CANCEL failing.  A
 186         * successful cancel sends DLM_NORMAL here.  If the
 187         * lock grant happened before the cancel arrived, you get
 188         * DLM_CANCELGRANT.
 189         *
 190         * There's no need for the double-ast.  If we see DLM_CANCELGRANT,
 191         * we just ignore it.  We expect the lock_ast() to handle the
 192         * granted lock.
 193         */
 194        if (status == DLM_CANCELGRANT)
 195                return;
 196
 197        lksb->lksb_conn->cc_proto->lp_unlock_ast(lksb, error);
 198}
 199
 200static int o2cb_dlm_lock(struct ocfs2_cluster_connection *conn,
 201                         int mode,
 202                         struct ocfs2_dlm_lksb *lksb,
 203                         u32 flags,
 204                         void *name,
 205                         unsigned int namelen)
 206{
 207        enum dlm_status status;
 208        int o2dlm_mode = mode_to_o2dlm(mode);
 209        int o2dlm_flags = flags_to_o2dlm(flags);
 210        int ret;
 211
 212        status = dlmlock(conn->cc_lockspace, o2dlm_mode, &lksb->lksb_o2dlm,
 213                         o2dlm_flags, name, namelen,
 214                         o2dlm_lock_ast_wrapper, lksb,
 215                         o2dlm_blocking_ast_wrapper);
 216        ret = dlm_status_to_errno(status);
 217        return ret;
 218}
 219
 220static int o2cb_dlm_unlock(struct ocfs2_cluster_connection *conn,
 221                           struct ocfs2_dlm_lksb *lksb,
 222                           u32 flags)
 223{
 224        enum dlm_status status;
 225        int o2dlm_flags = flags_to_o2dlm(flags);
 226        int ret;
 227
 228        status = dlmunlock(conn->cc_lockspace, &lksb->lksb_o2dlm,
 229                           o2dlm_flags, o2dlm_unlock_ast_wrapper, lksb);
 230        ret = dlm_status_to_errno(status);
 231        return ret;
 232}
 233
 234static int o2cb_dlm_lock_status(struct ocfs2_dlm_lksb *lksb)
 235{
 236        return dlm_status_to_errno(lksb->lksb_o2dlm.status);
 237}
 238
 239/*
 240 * o2dlm aways has a "valid" LVB. If the dlm loses track of the LVB
 241 * contents, it will zero out the LVB.  Thus the caller can always trust
 242 * the contents.
 243 */
 244static int o2cb_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb)
 245{
 246        return 1;
 247}
 248
 249static void *o2cb_dlm_lvb(struct ocfs2_dlm_lksb *lksb)
 250{
 251        return (void *)(lksb->lksb_o2dlm.lvb);
 252}
 253
 254static void o2cb_dump_lksb(struct ocfs2_dlm_lksb *lksb)
 255{
 256        dlm_print_one_lock(lksb->lksb_o2dlm.lockid);
 257}
 258
 259/*
 260 * Check if this node is heartbeating and is connected to all other
 261 * heartbeating nodes.
 262 */
 263static int o2cb_cluster_check(void)
 264{
 265        u8 node_num;
 266        int i;
 267        unsigned long hbmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
 268        unsigned long netmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
 269
 270        node_num = o2nm_this_node();
 271        if (node_num == O2NM_MAX_NODES) {
 272                printk(KERN_ERR "o2cb: This node has not been configured.\n");
 273                return -EINVAL;
 274        }
 275
 276        /*
 277         * o2dlm expects o2net sockets to be created. If not, then
 278         * dlm_join_domain() fails with a stack of errors which are both cryptic
 279         * and incomplete. The idea here is to detect upfront whether we have
 280         * managed to connect to all nodes or not. If not, then list the nodes
 281         * to allow the user to check the configuration (incorrect IP, firewall,
 282         * etc.) Yes, this is racy. But its not the end of the world.
 283         */
 284#define O2CB_MAP_STABILIZE_COUNT        60
 285        for (i = 0; i < O2CB_MAP_STABILIZE_COUNT; ++i) {
 286                o2hb_fill_node_map(hbmap, sizeof(hbmap));
 287                if (!test_bit(node_num, hbmap)) {
 288                        printk(KERN_ERR "o2cb: %s heartbeat has not been "
 289                               "started.\n", (o2hb_global_heartbeat_active() ?
 290                                              "Global" : "Local"));
 291                        return -EINVAL;
 292                }
 293                o2net_fill_node_map(netmap, sizeof(netmap));
 294                /* Force set the current node to allow easy compare */
 295                set_bit(node_num, netmap);
 296                if (!memcmp(hbmap, netmap, sizeof(hbmap)))
 297                        return 0;
 298                if (i < O2CB_MAP_STABILIZE_COUNT)
 299                        msleep(1000);
 300        }
 301
 302        printk(KERN_ERR "o2cb: This node could not connect to nodes:");
 303        i = -1;
 304        while ((i = find_next_bit(hbmap, O2NM_MAX_NODES,
 305                                  i + 1)) < O2NM_MAX_NODES) {
 306                if (!test_bit(i, netmap))
 307                        printk(" %u", i);
 308        }
 309        printk(".\n");
 310
 311        return -ENOTCONN;
 312}
 313
 314/*
 315 * Called from the dlm when it's about to evict a node. This is how the
 316 * classic stack signals node death.
 317 */
 318static void o2dlm_eviction_cb(int node_num, void *data)
 319{
 320        struct ocfs2_cluster_connection *conn = data;
 321
 322        printk(KERN_NOTICE "o2cb: o2dlm has evicted node %d from domain %.*s\n",
 323               node_num, conn->cc_namelen, conn->cc_name);
 324
 325        conn->cc_recovery_handler(node_num, conn->cc_recovery_data);
 326}
 327
 328static int o2cb_cluster_connect(struct ocfs2_cluster_connection *conn)
 329{
 330        int rc = 0;
 331        u32 dlm_key;
 332        struct dlm_ctxt *dlm;
 333        struct o2dlm_private *priv;
 334        struct dlm_protocol_version fs_version;
 335
 336        BUG_ON(conn == NULL);
 337        BUG_ON(conn->cc_proto == NULL);
 338
 339        /* Ensure cluster stack is up and all nodes are connected */
 340        rc = o2cb_cluster_check();
 341        if (rc) {
 342                printk(KERN_ERR "o2cb: Cluster check failed. Fix errors "
 343                       "before retrying.\n");
 344                goto out;
 345        }
 346
 347        priv = kzalloc(sizeof(struct o2dlm_private), GFP_KERNEL);
 348        if (!priv) {
 349                rc = -ENOMEM;
 350                goto out_free;
 351        }
 352
 353        /* This just fills the structure in.  It is safe to pass conn. */
 354        dlm_setup_eviction_cb(&priv->op_eviction_cb, o2dlm_eviction_cb,
 355                              conn);
 356
 357        conn->cc_private = priv;
 358
 359        /* used by the dlm code to make message headers unique, each
 360         * node in this domain must agree on this. */
 361        dlm_key = crc32_le(0, conn->cc_name, conn->cc_namelen);
 362        fs_version.pv_major = conn->cc_version.pv_major;
 363        fs_version.pv_minor = conn->cc_version.pv_minor;
 364
 365        dlm = dlm_register_domain(conn->cc_name, dlm_key, &fs_version);
 366        if (IS_ERR(dlm)) {
 367                rc = PTR_ERR(dlm);
 368                mlog_errno(rc);
 369                goto out_free;
 370        }
 371
 372        conn->cc_version.pv_major = fs_version.pv_major;
 373        conn->cc_version.pv_minor = fs_version.pv_minor;
 374        conn->cc_lockspace = dlm;
 375
 376        dlm_register_eviction_cb(dlm, &priv->op_eviction_cb);
 377
 378out_free:
 379        if (rc)
 380                kfree(conn->cc_private);
 381
 382out:
 383        return rc;
 384}
 385
 386static int o2cb_cluster_disconnect(struct ocfs2_cluster_connection *conn)
 387{
 388        struct dlm_ctxt *dlm = conn->cc_lockspace;
 389        struct o2dlm_private *priv = conn->cc_private;
 390
 391        dlm_unregister_eviction_cb(&priv->op_eviction_cb);
 392        conn->cc_private = NULL;
 393        kfree(priv);
 394
 395        dlm_unregister_domain(dlm);
 396        conn->cc_lockspace = NULL;
 397
 398        return 0;
 399}
 400
 401static int o2cb_cluster_this_node(unsigned int *node)
 402{
 403        int node_num;
 404
 405        node_num = o2nm_this_node();
 406        if (node_num == O2NM_INVALID_NODE_NUM)
 407                return -ENOENT;
 408
 409        if (node_num >= O2NM_MAX_NODES)
 410                return -EOVERFLOW;
 411
 412        *node = node_num;
 413        return 0;
 414}
 415
 416static struct ocfs2_stack_operations o2cb_stack_ops = {
 417        .connect        = o2cb_cluster_connect,
 418        .disconnect     = o2cb_cluster_disconnect,
 419        .this_node      = o2cb_cluster_this_node,
 420        .dlm_lock       = o2cb_dlm_lock,
 421        .dlm_unlock     = o2cb_dlm_unlock,
 422        .lock_status    = o2cb_dlm_lock_status,
 423        .lvb_valid      = o2cb_dlm_lvb_valid,
 424        .lock_lvb       = o2cb_dlm_lvb,
 425        .dump_lksb      = o2cb_dump_lksb,
 426};
 427
 428static struct ocfs2_stack_plugin o2cb_stack = {
 429        .sp_name        = "o2cb",
 430        .sp_ops         = &o2cb_stack_ops,
 431        .sp_owner       = THIS_MODULE,
 432};
 433
 434static int __init o2cb_stack_init(void)
 435{
 436        return ocfs2_stack_glue_register(&o2cb_stack);
 437}
 438
 439static void __exit o2cb_stack_exit(void)
 440{
 441        ocfs2_stack_glue_unregister(&o2cb_stack);
 442}
 443
 444MODULE_AUTHOR("Oracle");
 445MODULE_DESCRIPTION("ocfs2 driver for the classic o2cb stack");
 446MODULE_LICENSE("GPL");
 447module_init(o2cb_stack_init);
 448module_exit(o2cb_stack_exit);
 449
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